1. Field of the Invention
This invention relates generally to fluid line or injection port connectors in medical applications, and specifically to a needleless connector having a novel valve construction.
2. Prior Art
Fluid connections in medical applications have been typically made by inserting a needle into an injection port on the end of a tube. A common use of needle connections is in intravenous fluid lines. However, the use of needles in making fluid connections contributes to the hundreds of thousands of accidental needle sticks in health care professionals each year. The possibility of contracting infections from such needle sticks is a serious and deadly risk.
Although needles cannot be eliminated from the health care industry, their use can be reduced. One particular area in which they can be minimized or eliminated is fluid connections. Accordingly, various needleless connectors have been proposed or offered. U.S. Pat. No. 5,163,922 to McElveen, Jr. et al. (1992) shows a needleless connector with an elastomeric, conical valve head (32) biased against a conical valve seat (30) by a helical spring (38) to form a seal. The entire valve head is movable and non-compressible. When the male fitting (50) of a syringe, after having the needle removed, pushes against an elongated tip of the valve head, the valve head is pushed away from the valve seat to allow the passage of fluid.
U.S. Pat. No. 4,915,687 to Sivert (1990) shows a needleless connector with a resilient biasing member (40) for biasing a valve head (50) against a valve seat (23). The entire valve head is movable and non-compressible.
U.S. Pat. No. 4,683,916 to Raines (1987) shows a needleless connector having a valve head (50) in the form of a resilient disc preloaded against a valve seat. The center of the disc is fixed in position. A separate, elongated tip or plunger (60) distorts the disc by pushing the rim thereof away from the valve seat to allow fluid flow.
U.S. Pat. No. 5,280,876 to Atkins (1994) shows a quick disconnect for medical instruments. It uses a resilient, tubular sleeve (23) that coaxially surrounds a tubular stem (19). A side port (21) on the stem is unsealed when the sleeve is distorted by a male connector.
Known needleless connector devices such as those described above, suffer from a number of disadvantages. Many employ separate valve heads and biasing members, and some employ a tip or plunger separate from the valve head. Together with two-part housings, such known needleless connector devices use at least four separate parts. Because needleless connectors are disposable, their cost is of great importance. Having at least four separate parts result in a connector which is relatively expensive. In addition, some are relatively complicated, so that they are not really intended for disposable applications. For example, the same needleless connector devices have a port is orthogonal to axis of the tubular stem, so that it cannot be easily injection molded.
Certain of the known needleless connectors use a valve mechanism that incorporates an elongate cylindrical member that, when compressed to deformation, opens to permit fluid flow. A problem with this type of valve mechanism is that while open, the cylindrical (or like) member opposes the compressive force to keep it open. This opposing force can tend to cause luer slip connections to separate--particularly if only a friction connection is used.
Accordingly it can be seen that there is needed an needleless connector capable of ameliorating, if not overcoming, the disadvantages attendant with known needleless connectors.